enow.com Web Search

Search results

  1. Results from the WOW.Com Content Network
  2. Null hypothesis - Wikipedia

    en.wikipedia.org/wiki/Null_hypothesis

    Example: If a study of last year's weather reports indicates that rain in a region falls primarily on weekends, it is only valid to test that null hypothesis on weather reports from any other year. Testing hypotheses suggested by the data is circular reasoning that proves nothing; It is a special limitation on the choice of the null hypothesis.

  3. Type I and type II errors - Wikipedia

    en.wikipedia.org/wiki/Type_I_and_type_II_errors

    This is why the hypothesis under test is often called the null hypothesis (most likely, coined by Fisher (1935, p. 19)), because it is this hypothesis that is to be either nullified or not nullified by the test. When the null hypothesis is nullified, it is possible to conclude that data support the "alternative hypothesis" (which is the ...

  4. Statistical hypothesis test - Wikipedia

    en.wikipedia.org/wiki/Statistical_hypothesis_test

    An example of Neyman–Pearson hypothesis testing (or null hypothesis statistical significance testing) can be made by a change to the radioactive suitcase example. If the "suitcase" is actually a shielded container for the transportation of radioactive material, then a test might be used to select among three hypotheses: no radioactive source ...

  5. p-value - Wikipedia

    en.wikipedia.org/wiki/P-value

    For example, when testing the null hypothesis that a distribution is normal with a mean less than or equal to zero against the alternative that the mean is greater than zero (:, variance known), the null hypothesis does not specify the exact probability distribution of the appropriate test statistic.

  6. Student's t-test - Wikipedia

    en.wikipedia.org/wiki/Student's_t-test

    Student's t-test is a statistical test used to test whether the difference between the response of two groups is statistically significant or not. It is any statistical hypothesis test in which the test statistic follows a Student's t-distribution under the null hypothesis.

  7. One- and two-tailed tests - Wikipedia

    en.wikipedia.org/wiki/One-_and_two-tailed_tests

    This method is used for null hypothesis testing and if the estimated value exists in the critical areas, the alternative hypothesis is accepted over the null hypothesis. A one-tailed test is appropriate if the estimated value may depart from the reference value in only one direction, left or right, but not both. An example can be whether a ...

  8. Null distribution - Wikipedia

    en.wikipedia.org/wiki/Null_distribution

    In statistical hypothesis testing, the null distribution is the probability distribution of the test statistic when the null hypothesis is true. [1] For example, in an F-test, the null distribution is an F-distribution. [2] Null distribution is a tool scientists often use when conducting experiments.

  9. Z-test - Wikipedia

    en.wikipedia.org/wiki/Z-test

    How to perform a Z test when T is a statistic that is approximately normally distributed under the null hypothesis is as follows: First, estimate the expected value μ of T under the null hypothesis, and obtain an estimate s of the standard deviation of T. Second, determine the properties of T : one tailed or two tailed.